Apparatus for sizing tubing



Feb. 12, 1952 B, E, FRANK APPARATUS FOR SIZING TUBING Filed March 14, 195ol l l I l l I I I 1 4 I l I l I l /N VEN 70E 55E/mea T fen/wr //S FTTOQ/VEYS Patented Feb. 12, 1952 UNITED STATES PATENT OFFICE 2,585,450 APPARATUS FOR slz'ING TUBING Bernard E. Frank, Rochester, N'. Y, ass'ignor to General` Motors Corporation,l Detroit, Mich., 'a corporation of Delaware Application March 14, 1950, seramo. 149,563 z Claims. (c1. s-80.5)

Thisinvention relates toy apparatus for sizing the' end portion of a length of tubing. In anapparatus of this kind used heretofore, a length of tubing is gripped between clamps while the sizing punch is caused to be moved into the end of the tubing to expand the end portionto the required diameter. The extent to which the portion of the end tubing is sized or ilared is dependent upon the distance between the end of the tubing and the sizing punch in its fully re tracted position and upon the stroke of the punch.

An object of the present invention is to provide apparatus for sizing the end portion ci a piece of tubing regardless of the distance, within certain limits, between the end of the tubing and the punch in its retracted position, thereby avoiding the necessity of accurate location of the end of the tubing in order that the length of the sized or flared portion of the tubing will be uniform.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a plan view of the sizing apparatus involving the present invention.

Fig. 2 is a sectional view on line 2 2 of Fig. l.

Figs. 3 and 4 are views similar to Fig. 2, showing the apparatus in different operating positions.

Figs. 5, 6 and 7 are sectional views, respectively, on lines 5 5, 6 6 and 'I 'l of Fig. 2.

The apparatus comprises a cylindrical frame member IU adapted tol be received within the cylindrical bore of a guiding member (not shown) and having a threaded hole ll for receiving a threaded coupling member (not shown) which connects the frame IEI with an operating mechanism such as a piston located in a cylinder which receives pressure iiuid to cause the frame I- to be advanced and retracted relative to the tubing. Frame IDl has a central cylindrical bore I2 which receives and guides a bar I3 having a cylindrical portion I4 having a sliding fit with the bore I2. Bar I3 has a longitudinal rib or key portion le received by a longitudinal groove It in frame te whereby rotation of bar I3 relative to trame le is prevented.

The bore I 2 of frame IB- receives a block I1- whicli is generally of cylindrical contour and which has an air venting groove I8v and a groove I9 receiving that portion of the rib I5 which isv above the groove I6 of'f'rame lil.v Thus Vthe block I'I which has a sliding nt within the frame II) is prevented from rotating. n

Block II has a threaded bore coaxial with frame I0 which receives 'a screw plug 20y and 'a threaded shank' 2| of a sizing punch 22 having asliding ilt with the central 'bore in the cylindrical portion I 4 of bar' I3. The plug 20 and the shank 2I are screwed into the block Il as far as they will go. The plug 2B may be one of several different lengths determined in accordance with the required normal distance between the left end of the bar I3 and the leftend of punch 22'. To adapty the apparatus for a particular sizing r operation, a plug 20' of the re'duired length is selected. To prevent unscre'wing of the punch 22 relative to block ILa set screw 23 isv tightenedto force a soft metal pl-ug' 24 against thel threaded shank 2l of punch 2.2'.A Y

A spring 25j surrounding punch 2'2/ and confined under compression between block I'I andportion I'4 of the bar I3 urges' said bar to the left, said motion being limited by engagement oi portion I4 with a plate 26 which screws 2l secure to frame Ill. Spring 25"A urges block I 'I tol the right into engagement withl a roller 30 journaled on a pin 3| carried by a lever 3-2 journaled on a pin 33 supported by frame IIJ; A pin 34 'supported by frame I0 retains a torsion spring 35 having one end 33V connected with framev Il? and an end 3l' connected with vIev'er 321. Spring 35 urges lever 32 countercloekwise and roller 30 into engagement with an upper surface of portion [5d of rib 5'.

Usually the tube T" is clamped in a fixed position and the frame Il! is moved. However, the frame Ill can be xe'd and the tubing can be movedy axially by moving the grippers. In the following explanation of the mode of operation of the apparatus, the frame I-'D is considered xed and the' tubing T axially movable. Let it be assumed that, initially, the right end of tubing T is in the position shown in Fig. 2. As' tubing T moves to the righ-t relative to frame Id, the punch enters it since, at first.- the punch cannot move right because right movement of block Il' is" o'b'e' structed by a device including the roller 341 and lever 32 when located as shown in Fig. 2'.` Itis apparent that during the rst partof relative i movement between the tubing and the frame ill,

the tubing has engaged the part I4', which` serves as an abutment and has moved the bar I3 from the position shown in Fig".I 2' to that shown in Fig. 3; At the endi of said firs-t part of this" relativ'e'- movement, the rib I5 of the barV I3` has carnmed roller 3B from the position shown in Fig. 2. to that shown in Fig. 3 due to engagement with roller 3@ `:by an inclined camming surface 15b of rib i5. During this movement of roller 3U, it has moved away from end surface I'Ia of block l1 (at right angles to its direction of movement) into engagement with oblique surface 1lb, thereby causing the force exerted by spring 35 against the surface I'lb, to the roller 30 to be on a center line represented by the dot-dash line 40 which is at right angles to surface Ilb and intersects the point of tangency of surface I'Iband roller 30. Since this center line is substantially above the pivotal axis of the lever 32 at the center of pin 33, spring 31 is overcome andlever 32 is caused. to move from the position shown in Fig. 3 toward the position shown in Fig.. 4, as tubing T moves from the position shown in Fig. 3 to the position shown in Fig. 4.

During this movementfof the lever 32, there is no relative movement between punchl 22 and bar I3. Therefore the distance between the left end of punch 22 and the left end of abutment portion i4 of bar i3 remains unchanged. It is therefore apparent that the extent to which the tubing T receives the punch 22 is determined by two factors, namely, the distance to which the punch 22 normally extends to the left of the abutment portion I4 of the bar i3 and the distance through which bar I3 moves to cam the roller 30 from the position shown in Fig. 2 to that shown in Fig. 3. Therefore the initial distance between tubing T and the punch 22 can vary to an extent equal to that displacement of bar I3 relative to frame I which takes place to cause cam b to move roller 38 from normal position shown in Fig. 2 in which it prevents relative movement between block Il and frame IU to the position shown in Fig. 3 in which the function of roller 3 is nullified. The operation of the parts described would be the same whether the relative movement .be-- tween the punch 22 and the tube T is effected by a reciprocatory movement of the frame l) which carries the punch 22, or of the tube. Obviously, this reciprocatory movement of the frame ID or the tube T will be sucient to size pieces of tubing uniformly although the initial distance between the punch and the tubing may vary to the stated extent.

Whether the frame IB is advanced to the left relative to the tubing T and is retracted to the right or the tubing is advanced to the right and retracted to the left, Figs. 3 and 4 show relative positions of parts of the punch apparatus during advancement thereof. Relative retraction between the frame l0 and the tubing causes return of parts to the normal positions shown in Figs. 1 and 2.

During a first part of the retraction of frame i0, the punch 22 remains in engagement with the tubing T while frame l0 moves into such position that spring 31 can return roller 3B to a position upon the upper surface of rib l5. During further retraction of the frame l0, a pin 38 carried by the frame engages block Il to cause removal ofthe punch 22 from the tubing T and spring 25 is permitted to expand to press block H against roller 3D and the abutment I4 of bar I3 against plate 26. As bar i3 moves left relative to frame I, cam surface 15b of rib l5 moves left relative to roller and spring 31 forces roller 3U against surface |511 of rib l5, spring 25 having lost compression to the extent that spring 31 is able to perform this function.

While the embodiment ofthe present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

l. A sizing punch apparatus for use with a tube flaring machine having a tubing gripper and a mechanism for effecting relative advancing and retracting movements between a Sizing punch and the tubing retained by the gripper, said apparatus comprising a frame, a bar Supported by the frame for movement longitudinally of the tubing and having an abutment portion for engagement by the tubing, a block supported by the frame for relative movement longitudinally of the tubing and spaced from said abutment, a punch attached to the block and extending therefrom through the abutment a certain distance from the surface of the abutment facing the tubing, yielding means transmitting motion from the bar to the block, a device carried by the frame and normally conditioned for preventing relative movement between the block and frame whereby, during relative movement between the frame and the tub-. ing, a portion of the punch is received by the'.

tubing before engagement between the tubing and the abutment and then the abutment is moved relative to the block as an additional portion of the punch is received by the tubing, means actu-- ated in response to said movement of the abutment relative to the block for rendering said device unable to prevent relative movement between the block and frame whereby reception of the punch by the tubing ceases as advancement of the frame continues, and means provided by the frame for engaging the block during relative retraction between the frame and tubing in order to remove the punch from the tubing.

2. A sizing punch apparatus for use with a tube flaring machine having a tubing gripper and a mechanism for effecting relative advancing and retracting movement between a sizing punch and the tubing retained by the gripper, said apparatus comprising a frame, a bar supported by the frame for movement longitudinally of the tubing and having an abutment for engagement by the tubing, a block supported by the frame for movement longitudinally of the tubing and spaced from said abutment, a punch attached to the block and extending therefrom through the abutment a certain distance from the surface of the abutment facing the tubing, a helical coil compression spring surrounding the punch and confined between the abutment and the block to urge them apart, a stop attached to the frame and normally engaged by the bar to resist separation of the bar from the block, means for normally opposing separation of the block from the abutment and comprising a lever pivotally supported by the frame and a roller carried by the lever, said block having an end surface at right angles to the direction of relative movement between the punch and the tubing, said end surface being normally engaged by the roller, said block having a surface inclined from the plane of the rst mentioned surface and away from the lever, a second spring normally holding the lever in position such that the roller is engaged by the rst mentioned surface of the block, a cam provided by the bar for moving the roller against the action of the second spring from normal position to a position in which the roller engages the inclined surface of the block, whereby the leverage of the force which the first spring applies to the lever increases to a value such that the second spring is overcome by the rst spring and 5 the roller ceases to retain the block, said cam functioning during a certain movement of the bar abutment relative to the punch, and means provided by the frame for engaging the block during relative retraction between the frame and the tubing in order to remove the punch from the tubing.

BERNARD E. FRANK.

REFERENCES CITED The following references are of record in the tile of this patent:

6 UNITED STATES PATENTS Number Number Name Date Coielder July 21, 1914 French Apr. 13, 1937 Stevens Apr. 4, 1939 FOREIGN PATENTS Country Date Germany Oct. 4, 1927 

